pH simulations play a crucial role in modeling anaerobic digestion processes. Visual Water, a water chemistry software tool, provides a reliable pH prediction routine along with an automated mathematical uncertainty analysis. Its reliability was validated and compared to the original Anaerobic Digestion Model No. 1 (ADM1).

Abstract

In anaerobic technology, pH values are crucial for targeted volatile fatty acid production. While pH dynamics can be modeled using the Anaerobic Digestion Model No. 1 (ADM1), simulation results may be biased. To address this issue, the pH prediction routine of Visual Water, a specialized water chemistry simulator, was validated. Unlike ADM1, it accounts for ionic strength and activities while also providing an automated uncertainty analysis. The analysis revealed Visual Water simulations to better fit measured pH data from acidic solutions in a miniaturized stirred-tank reactor.